Raspberry Pi-based smart bartender using a simple Python server & HDMI display. This project was forked from a HackerShack project but rewritten from the ground up. This version uses peristaltic pumps controlled by a Raspberry Pi, two Gpio buttons for controls, and a small HDMI display pointed to a local Python server that dispenses drinks.
JSON configs are used for both the pump attributes (e.g. ingredient names, flow rates) and the drinks themselves. On startup, the server filters the drink list to only include drinks with all ingredients available in the pump configs.
The pump configuration persists information about pumps and the liquids that they are assigned to. An pump entry looks like this:
"pump_1": {
"flowrate": 20,
"name": "Pump 1",
"pin": 17,
"value": "gin"
}
Flowrate indicates the time (in seconds) that it takes for this pump to pull 1oz of liquid through the tube. This can be adjusted to adjust pump timings for faster or slower pumps (or for adjustments like pumps with carbonated ingredients, which may pull less liquid volume per second than non-carbonated liquids).
Each pump key needs to be unique. It is comprised of name, pin, and value. name is the display name shown to the user on the pump configuration menu, pin is the GPIO pin attached to the relay for that particular pump, and value is the current selected drink. value doesn't need to be set initially, but it will be changed once you select an option from the configuration menu.
The drinks configuration maps pump value entries to ingredients to configure the time required per pump. All ingredient values are in units of ounces and will be scaled using the flowrate pump config to determine the specific timing.
The name will both be the name displayed, and unless image is provided, the background image for the menu item on the server. garnish displays an optional message for a few seconds after the drink is completed.
{
"name": "Sazerac",
"ingredients": {
"absinthe": 0.25,
"simple syrup": 0.5,
"rye whisky": 1.5
},
"garnish": "Add three drops of Peychaud's bitters and lemon peel"
}
The Python server uses a set of stub libraries for gpio and automatically switches to these libraries instead of the real gprio libraries when running off of a Raspberry PI. This allows development of the drink server on devices other than the Raspberry Pi.
The testing directory contains several utilities for testing components of the Raspberry Pi:
-
calibrate_pumps.py: Runs a given pump for a fixed time. Useful for determining the flowrate of individual pumps to pour one ounce of liquid. -
run_all_pumps.py: Runs all pumps at once. Useful for rinsing or washing the pump tubes -
run_pump.py: Runs a single pump until the script is quit -
test_buttons.py: Attaches a listener to print debug when gpio buttons are pressed -
test_pumps.py: Tests both the pump wiring and total amperage draw by individually starting each pump, then starting them all at once in sequence.
First, make sure to download this repository on your raspberry pi. Once you do, navigate to the downloaded folder in the terminal:
cd ~/path/to/directory
and install the dependencies
sudo pip install -r requirements.txt
You can start the bartender by running
sudo python server.py
You can configure the bartender to run at startup by starting the program from the rc.local file. First, make sure to get the path to the repository directory by running
pwd
from the repository folder. Copy this to your clipboard.
Next, type
sudo vim /etc/rc.local
to open the rc.local file. Next, press i to edit. Before the last line, add the following two lines:
exec 1>/tmp/rc.local.log 2>&1 # send stdout and stderr from rc.local to a log file
set -x # tell sh to display commands before execution
cd your/pwd/path/here
sudo modprobe uinput
sudo python3 server.py
your/pwd/path/here should be replaced with the path you copied above. These commands enable the GPIO pins and start the server.
Once the server launches at startup, follow this guide to set up autostart for th pi user, and add the following two lines to run chrome at startup:
@chromium-browser --kiosk http://localhost:5000
@unclutter
This command launches Chromium full-screen and hides the cursor.